The present invention relates to video signal processing methods and apparatus. More particularly, the invention relates to color video recording and reproducing systems in which the chroma and luminance components of the video signal are separated and passed through separate processing channels, and are later combined to produce a signal for recording on tape, or for reproducing in a television receiver.
The chroma and luminance signals have initial fixed frequency and phase relationships. In passing through separate processing paths, the phase relationship of the chroma signal may become displaced relative to the reference luminance signal. In certain improved video recording and reproducing systems, the phase displacement of the chroma signal relative to the reference luminance signal cannot be tolerated.
It is therefore an object of the invention to detect a phase displacement of a chroma signal relative to a reference luminance signal, and to restore the chroma signal to phase synchronization with the reference luminance signal.